New Amp / old speakers

[TmoT]

I have old JBL Decase 36 studio monitors that have been GREAT forever, but I recently bought a Pule 500 watt / 4 channel amp and no one of my JBLs is rattling.
I run 4 channels so I thought I was running 135 watts / channel and the JBLs would be OK
Those 4 channels are pushing 8 speakers in 4 rooms, so 500/8= 62.5 watts / channel... I think???? maybe???

They were like 35 watt speaker when new (I think)
I wonder did the new amp fry the coils?
Maybe they just finally gave out after 40 years? (one re-build)

 

[-Jim-]

I too have a pair of JBL Decade L36 speakers. I had them re-coned when the foam surrounds on the bass drives "rotted" off.

During a Reno a few years back my wife decided these were too large for her new Decor and they've been retired to the Basement storage area, (Still working great!) replaced with much smaller JBLs that IMHO don't sound quite as good. According to the JBL Decade L36 Manual (which I have in .pdf) the Power Capacity is 50 watts continuous.

And they will run just fine if a "clean" signal is pushed to them at 50 watts but usually they will be at a fraction of that level. These JBL Decade L36s (especially for JBLs) aren't particularly sensitive (with 1 watt producing 76 dB at 15 feet => about 90 dB at 3 feet) but are no slouch. So you wouldn't be driving them with 135 watts.

You are getting confused between what an amplifier is capable of, and what a speaker will use in normal use. It's fine to have say a 500 watt amplifier (as long as the signal is not distorted) connected to speakers like a JBL Decade L36 with a Power Capacity of 50 watts continuous. As soon as a speaker sound a bit distorted it is being over driven (if the amplifier is clipping or you are exceeding the capability of the speaker - but those JBLs would be so loud!)

You state "those 4 channels are pushing 8 speakers in 4 rooms " Can you provide the wiring details from the Pule 500 watt / 4 channel amp to the speakers and the specifications for the amplifier as well? It may be they way they are hooked up that is causing problems.

Although the JBLs may also be at fault. Can you describe this rattling and how loud it is when it occurs?

 

[Eppie]

Says on-line the L36 handles 50W max, which would be continuous RMS power. Those numbers and your amp power are rated maximums. You'd have to have it pretty loud to put that much continuous power into them but it would be possible to damage them if driven too hard or into distortion. "Rattling" is a little vague. If you listen up close, is it from one particular driver or from the cabinet? If you press on both sides of the woofer cone equally, does it move freely or can you hear the voice coil scrape the magnet? (Press gently and don't bottom out the voice coil on the magnet.)

You might still be able to get them repaired. Depends upon how attached you are to them.

 

[Pogre]

You have a 4 channel amp running 8 speakers? Did I read that correctly? If so how do you have them hooked up? Are they all 8 ohm speakers?

 

[TmoT]

I too have a pair of JBL Decade L36 speakers. I had them re-coned when the foam surrounds on the bass drives "rotted" off.

During a Reno a few years back my wife decided these were too large for her new Decor and they've been retired to the Basement storage area, (Still working great!) replaced with much smaller JBLs that IMHO don't sound quite as good. According to the JBL Decade L36 Manual (which I have in .pdf) the Power Capacity is 50 watts continuous.

And they will run just fine if a "clean" signal is pushed to them at 50 watts but usually they will be at a fraction of that level. These JBL Decade L36s (especially for JBLs) aren't particularly sensitive (with 1 watt producing 76 dB at 15 feet => about 90 dB at 3 feet) but are no slouch. So you wouldn't be driving them with 135 watts.

You are getting confused between what an amplifier is capable of, and what a speaker will use in normal use. It's fine to have say a 500 watt amplifier (as long as the signal is not distorted) connected to speakers like a JBL Decade L36 with a Power Capacity of 50 watts continuous. As soon as a speaker sound a bit distorted it is being over driven (if the amplifier is clipping or you are exceeding the capability of the speaker - but those JBLs would be so loud!)

You state "those 4 channels are pushing 8 speakers in 4 rooms " Can you provide the wiring details from the Pule 500 watt / 4 channel amp to the speakers and the specifications for the amplifier as well? It may be they way they are hooked up that is causing problems.

Although the JBLs may also be at fault. Can you describe this rattling and how loud it is when it occurs?

OK, so here is the diagram for the PYLE.



It’s very simple and not stereo, only one channel goes out. It was mis-marketed. So all speakers are getting the same signal. Not good on certain 1960s Beetles tunes, haha. No problem with modern music.



It sounded great at first and solved my ‘different rooms / different volume’ challenge, but seems to have degraded……

I too have a pair of JBL Decade L36 speakers. I had them re-coned when the foam surrounds on the bass drives "rotted" off.

During a Reno a few years back my wife decided these were too large for her new Decor and they've been retired to the Basement storage area, (Still working great!) replaced with much smaller JBLs that IMHO don't sound quite as good. According to the JBL Decade L36 Manual (which I have in .pdf) the Power Capacity is 50 watts continuous.

And they will run just fine if a "clean" signal is pushed to them at 50 watts but usually they will be at a fraction of that level. These JBL Decade L36s (especially for JBLs) aren't particularly sensitive (with 1 watt producing 76 dB at 15 feet => about 90 dB at 3 feet) but are no slouch. So you wouldn't be driving them with 135 watts.

You are getting confused between what an amplifier is capable of, and what a speaker will use in normal use. It's fine to have say a 500 watt amplifier (as long as the signal is not distorted) connected to speakers like a JBL Decade L36 with a Power Capacity of 50 watts continuous. As soon as a speaker sound a bit distorted it is being over driven (if the amplifier is clipping or you are exceeding the capability of the speaker - but those JBLs would be so loud!)

You state "those 4 channels are pushing 8 speakers in 4 rooms " Can you provide the wiring details from the Pule 500 watt / 4 channel amp to the speakers and the specifications for the amplifier as well? It may be they way they are hooked up that is causing problems.

Although the JBLs may also be at fault. Can you describe this rattling and how loud it is when it occurs?

OK, so here is the diagram for the PYLE.

It’s very simple and not stereo, only one channel goes out. It was mis-marketed. So all speakers are getting the same signal. Not good on certain 1960s Beetles tunes, haha. No problem with modern music.

It sounded great at first and solved my ‘different rooms / different volume’ challenge, but seems to have degraded……

 

[TmoT]

Says on-line the L36 handles 50W max, which would be continuous RMS power. Those numbers and your amp power are rated maximums. You'd have to have it pretty loud to put that much continuous power into them but it would be possible to damage them if driven too hard or into distortion. "Rattling" is a little vague. If you listen up close, is it from one particular driver or from the cabinet? If you press on both sides of the woofer cone equally, does it move freely or can you hear the voice coil scrape the magnet? (Press gently and don't bottom out the voice coil on the magnet.)

You might still be able to get them repaired. Depends upon how attached you are to them.

Hard to define the sound, but from the 10 inch woofer, which I replaced the foam core on years ago. When I put my fingers on that speaker, the 'scratchy" sound stops. The foam is excellent. It is not scraping the magnet either.
THanks.

 

[Pogre]

Hard to define the sound, but from the 10 inch woofer, which I replaced the foam core on years ago. When I put my fingers on that speaker, the 'scratchy" sound stops. The foam is excellent. It is not scraping the magnet either.
THanks.

You could turn the power off and gently push in on the woofer. It should be nice and smooth. If it rubs or scratches it might be fried.

 

[-Jim-]

OK, so here is the diagram for the PYLE.



It’s very simple and not stereo, only one channel goes out. It was mis-marketed. So all speakers are getting the same signal. Not good on certain 1960s Beetles tunes, haha. No problem with modern music.



It sounded great at first and solved my ‘different rooms / different volume’ challenge, but seems to have degraded……



OK, so here is the diagram for the PYLE.

It’s very simple and not stereo, only one channel goes out. It was mis-marketed. So all speakers are getting the same signal. Not good on certain 1960s Beetles tunes, haha. No problem with modern music.

It sounded great at first and solved my ‘different rooms / different volume’ challenge, but seems to have degraded……

The Pyle Amp is a bit sketchy. It seems like a Stereo Amplifier with 4 stereo channels out but it mixes it down into Mono to each of the 4 stereo pairs of speakers. If you bought it new from Amazon, I suggest you return it and get something better.

Do you have 4 pairs of JBLs connected to the Pyle? According to the video below the amp is capable of 60 Watts RMS into 8 Ohms (which is what your L36s are rated nominally at.) The manual is next to useless.

Can you hook up the L36 that makes the "scratchy" sound to another amp and see if it does the same? Can you hook up a different L36 to the wires feeding the scratchy one and see if it too now sound the same. If so it's the Pyle and not the L36.

 

[Pogre]

OK, so here is the diagram for the PYLE.



It’s very simple and not stereo, only one channel goes out. It was mis-marketed. So all speakers are getting the same signal. Not good on certain 1960s Beetles tunes, haha. No problem with modern music.



It sounded great at first and solved my ‘different rooms / different volume’ challenge, but seems to have degraded……



OK, so here is the diagram for the PYLE.

It’s very simple and not stereo, only one channel goes out. It was mis-marketed. So all speakers are getting the same signal. Not good on certain 1960s Beetles tunes, haha. No problem with modern music.

It sounded great at first and solved my ‘different rooms / different volume’ challenge, but seems to have degraded……

I think what he means by a diagram is how exactly do you have the speakers wired to the amp. They could be in series or parallel, which makes a huge difference. What the amp is rated to handle would help too. Is it rated down to 4 ohms, or even 2 ohms?